On-Pump vs. Off-Pump Coronary Bypass Operations

“On-Pump” Surgery –

Cardiopulmonary bypass (CPB) is a technique that temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. The CPB pump itself is often referred to as a “heart–lung” machine.

The first successful open heart procedure on a human utilizing the heart lung machine was performed by John Gibbon on May 6, 1953 at Thomas Jefferson University Hospital in Philadelphia. Since then coronary artery bypass with the CPB machine has become routine and has indeed become one of the most commonly performed surgical procedures in America.

80% of all coronary bypass operations are performed using the CPB machine and advocates of this technique point to several advantages that have been borne out in randomized, controlled studies, including:

More complete revascularization – Better chance of bypassing all of the diseased vessels at one time

Prolonged graft patency – Better chance that the bypasses will stay open and useful for a long time

Lower mortality rate at 1 year

“Off-Pump” Surgery –

In the last decade, off-pump coronary artery bypass surgery was developed partly to avoid the complications of cardiopulmonary bypass during cardiac surgery. Some surgeons in the medical community believed cardiopulmonary bypass caused a post-operative cognitive decline known as postperfusion syndrome (informally called “pumphead”).

While the learning curve for learning how to perform off-pump coronary bypass surgery is steep, surgeons who perform this surgery frequently have been sown to be able to achieve similar results to those performing on-pump surgery.

Recent Duke University Research Study Published in the New England Journal of Medicine

Off-Pump surgery associated with increased risk of:

death within the first year after surgery

need for repeat revascularization

incomplete revascularization

early graft closure

risk of having another heart attack

There was no difference in:

Length of ICU or hospital stay

Requirement of blood transfusion

Time on ventillator

Return to the hospital for re-admission

While the off-pump approach may still have a particularly important role in selected patients at high risk for neurologic events and those with diseased ascending aortas, based on these results, any patient who is a reasonable candidate for on-pump bypass, even if the option for off-pump exists, should undergo on-pump surgery.